I'd say you're getting totally ripped off by the Bearded One. Even BT standard rates are 18.3 p/min (daytime) or 12.6 p/min (evenings/weekends). I pay a fraction of that through my provider (Eclipse).

Whatever the phone rates, if I were your daughter, I'd just dispute the charge, rather than risking a frustrating and long phone call, potentially being passed from pillar to post. Make it DFS's problem, not hers!

I've never had any problems with DFS delivering at the gate. However, your story worries me, because I will often use my spare $$$ rather than my credit card to buy duty free.